1. Field of the Invention
The invention relates to a coupling; in particular, the invention relates to a coupling that can prevent a shaft of a reflectivity-measuring device from skidding.
2. Description of the Related Art
In the semiconductor manufacturing process, there is a process to electroplate a film on a wafer. After such a process is completed, a reflectivity-measuring device measures the thickness of the film.
Referring to FIG. 1, the reflectivity-measuring device 30 connects with a motor 20 by a coupling 10. A first shaft 31 of the reflectivity-measuring device 30 and a second shaft 21 of the motor 20 are inserted into the coupling 10 separately. Therefore, the motor 20 drives the reflectivity-measuring device 30 through the coupling 10 in order to focus.
Referring to FIG. 2a, FIG. 2b and FIG. 2c, the coupling 10 comprises a main portion 11 and plural screws 18. A first hole 12 and a second hole 13 are formed on both end surfaces of the main portion 11. The first hole 12 is used for the first shaft 31 inserting therein, and the second hole 13 is used for the second shaft 21 inserting therein. A first screw hole 14 and a second screw hole 15 are formed on the circumference surface of the main portion 11. The first screw hole 14 and the second screw hole 15 are used for the screws 18 inserting therein. Furthermore, a first slot 16, communicating with the first hole 12 and the first screw hole 14, is formed on the main portion 11. A second slot 17, communicating with the second hole 13 and the second screw hole 15, is formed on the main portion 11. By means of the deposition of the first slot 16 and the second slot 17, the first hole 12 and the second hole 13 have a larger space before the first shaft 31 and the second shaft 21 are inserted into the first hole 12 and the second hole 13. After the first shaft 31 and the second shaft 21 are put in the first hole 12 and the second hole 13 separately, the screws 18 are screwed to the first screw hole 14 and the second screw hole 15 separately in order to decrease the gaps of the first slot 16 and the second slot 17. As a result, the sizes of the first hole 12 and the second hole 13 become smaller, the first shaft 31 and the second shaft 21 are locked inside the main portion 11.
However, since the diameters of the first shaft 31 and the second shaft 21 are extremely small, the screws 18 cannot lock the first shaft 31 and the second shaft 21 inside the main portion 11 completely. Furthermore, the output of the first shaft 31 is usually large, the skid between the first shaft 31 and the main portion 11 easily occurs. Hence, during the focus of the reflectivity-measuring device 30, errors also easily occur.
In view of the disadvantages of the aforementioned conventional coupling, the invention provides a coupling that can prevent a shaft of a reflectivity-measuring device from skidding.
Accordingly, the invention provides a coupling for connecting a reflectivity-measuring device with a motor. The reflectivity-measuring device has a first shaft, and the motor has a second shaft. The coupling comprises a main portion having a first hole and a second hole. The first hole is used for the first shaft inserting therein, and the second hole is used for the second shaft inserting therein. The main portion further comprises a third hole, communicating with the first hole, and a first non-skid member, inserting into the third hole and abutting the first shaft located inside the first hole.
Furthermore, the main portion further comprises a fourth hole, communicating with the second hole, and a second non-skid member, inserting into the fourth hole and abutting the second shaft located inside the second hole.
Furthermore, the number of the third hole is not less than one, the number of the first non-skid member is not less than one, the number of the fourth hole is not less than one, and the number of the second non-skid member is not less than one.
Furthermore, the invention provides a coupling for a reflectivity-measuring device. The reflectivity-measuring device has a first shaft. The coupling comprises a main portion having a first hole. The first hole is used for the first shaft inserting therein. The main portion further comprises a third hole, communicating with the first hole, and a first non-skid member, inserted into the third hole and abutting the first shaft located inside the first hole.